Melting, converting, and refining metals



July 30, 1940.i v. sTERr-:NTAL

MELTING, CONVERTING, AND REFINING METALS Filed Dec. 8, 1958 .PatentedJuly 30, y1940 2,209,481 MELTING, coNvEa'rlNG, AND REFINING METAL VoltSterental, Turin, Italy, assignor of three- I3 fourths to Davide Jona,Giulio Jona, and Raffaele Jona, lall of Turin, Italy ApplicationDecember 8, 1938, Serial No. 244,648

In Italy December 17, 1937 (Cl. 'I5-63) This invention has for itsobject a process by 1 Claim.

which it is possible to effect, without any transfer of the materialunder treatment, the melting conversion and rening of copper fromresidues of mechanical manufacture of copper and zinc alloys andrecovery of zinc in form of zinc oxide.

.These residues and waste products are geni and the residual heat andby-products may berecovered. The furnace is substantially constituted bya large retort of refractory material rotatably mounted on trunnions sothat it may be brought into different positions within a range duce onoxidising a considerable heat are added,

then the door is closed and the retort is rotated in such manner -as tobring the burner upwards and melting is started by means of said burner.Once the melting of the charge is started, working of the burner isstopped while the blower is operated and the retortis gradually broughttowards its vertical position and kept during conversion in suchposition that as the metal melts it forms a coating of a few centimeters,thickness over the blower nozzles.

The furnace during this time works as a converter and melting iseffected owing to the heat produced by exothermal reactions of oxidationwhile the combustion products are collected, cooled, condensed andrecovered. When, at acertain stage of the process, the metal on reachinga certain concentration ytends to cool, the retort'` is returned to itshorizontal position, the blower is operated and blows the air on themelting bath. During this third stage the furnace works as areverberatory furnace eecting an oxidising melting and refining of themetal is continued; on removal of gases and reduction the metal ismelted into cakes or ingots to supply to the trade.

The annexed drawing shows diagrammatically the invention.

Fig. 1 is a section of the retort perpendicular to the axis of therotating trunnions.

Fig. 2 is a conventional section of the oscillating trunnionsapproximately in the plane II-II of Fig. 1. Y'

p The furnace as illustrated is.broadly in the form of a steel retortvwith an inner lining of acid or basic refractory material according tothe de- 10 sired use.

The chamber I is limited by a belly portion 2 and a back portion ofsubstantially fiat cross section, a bottom I and a neck 5' bent towardsthe back portion throughv which the furnace is 15 charged. The backportion is provided in proximity to the bottom with a blower 6 andnozzles 1. The furnace is provided midway betweenbelly and rear portionwith trunnions 8 and 9,/ on which .the furnace `may rotate through 96 ormore, taking a horizontal position with its belly downwards; the furnaceis provided with a door I0, which must be tight-sealed once the furnacehas been charged. In the upper part of the back portion there are twoopenings: a wide one Il into which opens a conduit I2 and a smaller oneI3, in which opens the nozzle of a burner Il. 'I'he 'conduit 6a of theblower, conduit I2 and the conduit of the burner I4 are all rotatablyconnected on theaxis of the trunnions, so that the furnace may bebrought to any inclined position even during operation `of the conduits.The conduit I2, owing to the fact that the door I0 is tight-closed,carries the volatile and combustion products into condensers andarrangements for recovering the heat ,of the combustion products. Theburner nozzle is so positioned that the Iame is thrown into a whirlingmotion ensuring a thorough and uniform combustion.

The melting and rening process carried out in the above describedfurnace is as follows: y

If, for instance, residues y(turnings, chips, etc.) of copper alloys,such as brass, are to be treated, the furnace is so rotated as to bringits .belly downwards; lthe material is charged adding suitableslag-forming and other substances (iron, silicon, manganese, etc.)adapted to develop a strong heat during oxidation and the melting isstarted by means of the burner. When part of the, charge is melted andthe other `part is highly heated, operation of the burner is stopped andthe blower is started by bringing the furnace rst into a horizontalposition and then inclining it little by little as the llevel ofthe-bath reaches and slightly exceeds that of the blower nozzles. The

processes, at this stageof the work, owing to the cooling of theconverter.l the reiining should be continued in a reverberatory furnace,in the proc.- ess according to this invention it will be sufficient toreturn the furnace to its horizontal position, resume the heating )yoperating the burner and operate again the blower, which, at this stage,blows the air on the bath refining it through oxidation to about 99.8%.The work ends with the removal of gases and reduction of the4 bath by.

poling of course on previously removing the door Il).A The rened copperis at last discharged through the furnace outlet.

What I claim is:

l A process of melting, converting and refining copper and recoveringzinc from-residues of a1- loys containing such materials, consisting inintroducing the material to be treated together with slag-formingsubstances and substances develop- `ing heat dring oxidation, into aretortshaped furnace tiltable on a horizontal axis, sealing the f feedopening of the furnace and tilting the latter into 'the horizontalposition, heating the charge at its free surface, stopping the heatingwhen a part of the charge is melted, blowing air into the charge,tilting back simultaneously and gradually vthe furnace in such mannerthat, as the metal melts, the` level of the melted portion coverssomewhat the nozzle openings, discharging continuously'the volatileyproducts from the furnace for their recovery during blowing, returningthe furnace to its horizontal position when there is a tendency tocooling, resuming heating and then blowing air to activate combustionand finally 2o poling the charge. I VOLF STERENTAL.

